Individual study: The effect of applying creosote, sodium nitrite or urea to tree stumps on the spread of butt rot Heterobasidion annosum in Norway spruce Picea abies in a plantation woodland in Denmark
Vollbrecht G. & Jorgensen B.B. (1995) The effect of tree stump treatment on the spread rate of butt rot in Picea abies in Danish permanent forest yield research plots. Scandinavian Journal of Forest Research, 10, 271-277
Butt rot Heterobasidion annosum is considered the most damaging root pathogen of coniferous trees in the Northern hemisphere, infecting both Norway sprucePicea abies and Scots pine Pinus sylvestris. It causes butt rot in spruce which can be seen as rotting of the stem, and resinosis in pine. Butt and root rot impairs forest health and causes forest owners and industry losses as wood quality reduces as rot-damaged wood is not acceptable as sawn timber. An important aspect in the fight to control H.annosum is to reduce damage in already infected areas and to prevent its spread to new areas.
The effect of tree stump treatment with three potential chemical control agents on the spread rate of butt rot in Danish permanent forest yield research plots of pure Norway spruce was evaluated.
The effect of tree stump treatment with three different chemical agents on the spread rate of butt rot in Danish permanent forest yield research plots of pure Norway spruce Picea abies was asessed. The three chemicals tested were: creosote, 10% aqueous solution of sodium nitrite and 20% aqueous solution of urea.
To calculate butt rot spread rate, butt rot incidence and possible stump treatment in previous thinnings were used as variables in the subsequent thinnings.
In total, 59,000 Norway spruce stumps from 622 thinnings were used in the analyses. Each thinning was regarded as one observation.
If the previous thinning was carried out with urea applied to treat stumps, the spread rate of butt rot was less than 50% that of the spread rate if the previous thinning had been carried out without stump treatment. If stumps from the thinning prior to the previous thinning were treated with urea, the spread rate was less than one-third.
Sodium nitrite used to treat stumps also reduced butt rot spread rate but it was not as effective as urea. Creosote had no effect on the spread rate.
Plots on old hardwood forest sites showed a faster development of butt rot than either plots on old field sites or plots on old coniferous forest or old heathland sites.
Conclusions: Of the three treatments tested, the most effective was a 20% aqueous solution of urea applied to spruce stumps; a 10% aqueous solution of sodium nitrite was less effective, whilst creosote had no effect on butt rot spread rate.
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